Conventional technologies for capturing a shape of an object are largely classified into two groups. The first group scans shape information of an object by using an active sensor that uses lasers or pattern rays, and extracts a texture of a scanned mesh from a color image obtained by photographing the object. This group is used mainly to create a model of high quality by restriction to a still image.
The second group reconstructs shape information and surface color information of an object from image information obtained by photographing a shape of the object from multiple viewpoints, by using a passive camera. This group is classified, in more detail, into a stereo method in which 3D position information is reconstructed on the basis of triangulation using corresponding points of a stereo image and a volumetric method in which a voxel space containing voxels is predefined, and the voxels are projected to images so as to determine existence of the voxels using coincidence of colors in projection regions.
Recent studies enable multi-view image based reconstruction of a 3D shape model of an object to be carried out in order to realize a 3D shape model of high quality, in which case reconstruction of a 3D shape model of a static object itself is severely time-consuming. However, they show results very close to the reconstruction quality of laser scanners. On the other hand, reconstruction of a 3D shape model of a dynamic object depends mainly on silhouette information of multi-view images, in which case the 3D shape model of the dynamic object may be reconstructed in real time but its reconstruction quality is considerably low as compared with that of a 3D shape model of a static object.
As a result, in order to reconstruct a high-quality 3D shape model of a dynamic object, it is necessary to reconstruct 3D shapes of static objects under the assumption that a multi-view moving image obtained by photographing a dynamic object may be divided into multiple static objects in units of frames and express the 3D shape model of the dynamic object by accumulating the reconstructed 3D shapes of the static objects, but this is severely time-consuming. Moreover, although a state-of-the-art technology for reconstruction of a 3D shape model using graph-cut shows a reconstruction quality level similar to that of laser scanners, it is difficult to accurately satisfy restrictions against silhouettes of multi-view images and realize a same image when the reconstructed result is projected to multi-view images again.
As mentioned above, the conventional technologies for capturing a shape of an object are time-consuming in calculation for reconstruction of a static object and cause difficulties in reconstruction of a same 3D image of a dynamic object.